1. Field of the Invention
The present invention, in general relates to water valves and, more particularly, to devices that shut off the flow of water automatically upon detecting a fault condition.
Water shut-off valves and systems are known. Some of them are based on monitoring a continuous flow of water. The problem with such a system is that eventually an acceptable continuous flow, such as from a leaking valve in a toilet tank, will accumulate until a fault condition is indicated and shut off the flow of water when, in fact, a serious fault condition does not exist.
Also, certain other types of continuous flow systems are more complex and require that a second flow sensor be installed in a drain line and then connected to the system so as to determine when a protracted or excessive flow of water is nevertheless acceptable, because it is not then believed to be accumulating in the house. This is hardly foolproof as considerable damage may be occurring yet the water may eventually find its way to a drain. Also such a system is more complex to install and to maintain.
Still other known systems do not allow for varying conditions, such as occur during seasonal changes when, for example, a lawn is to be watered in the summer and then only on particular days, or for special situations such as when the family is away from the home on vacation. For example, some of these prior systems specifically require that physical installation of the system occur after water has already been acquired for sprinkler use, thereby rendering the system ineffective in detecting leaks involving the sprinkler system.
Other systems are not well suited for use in commercial installations where potentially high flow rates are likely to occur, and when, during normal use, a continuous flow may be present simply due to many users having intermittent requirements that occasionally result in a protracted uninterrupted continuous flow that can be misinterpreted as a fault condition (leak) that results in stopping the flow of water when it is not desired.
Accordingly, there exists today a need for a water shut-off valve and leak detection system that is immune to a continuous flow of water provided the quantity used is not excessive, is simple to install, is less expensive to manufacture, has settings that adapt to varying water usage patterns, and is suitable for use in commercial buildings as well as in private residences.
Clearly, such an apparatus is a useful and desirable device.
2. Description of Prior Art
Water shut-off valves and systems are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 5,000,224 to Olson, Jr., et al, Mar. 19, 1991; PA1 U.S. Pat. No. 5,251,653 to Tucker et al, Oct. 12, 1993; PA1 U.S. Pat. No. 5,267,587 to Brown, Dec. 7, 1993; PA1 U.S. Pat. No. 5,287,884 to Cohen, Feb. 22, 1994; PA1 U.S. Pat. No. 5,409,037 to Wheeler et al, Apr. 25, 1995; PA1 U.S. Pat. No. 5,464,038 to Kruto, Nov. 7, 1995; and PA1 U.S. Pat. No. 5,503,175 to Ravilious et al, Apr. 2, 1996.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.